Adjustable height seat

ABSTRACT

Mechanism operable to adjust the height of the seat in relation to the vehicle floor. The mechanism includes crossed levers arranged in pairs with the inner levers of the two pairs connected to one another by a torsion rod. The two pairs of levers are connected to one another by a transverse pivot shaft and corresponding ends of the outer levers of the pairs are connected to sliding pivot blocks. Wedge-shaped or cam-action plates arranged inwardly of the lever pairs are slidably connected to said shaft and also to a crossbrace assembly which is slidably forwardly and rearwardly of the seat relative to said pairs of crossed levers by means of a screw and nut mechanism.

United States Patent [1 1 Adams 1 1 ADJUSTABLE HEIGHT SEAT [75] Inventorf Albert John Adams, Middlesex,

England [73] Assignee: A. W. Chapman Limited,

London, England [30] Foreign Application Priority Data FOREIGN PATENTS OR APPLICATIONS Great Britain 248/419 1 Nov. 112 1974 1.107915 5/1961 Germany 248/421 537,355 6/1941 Great Britain ..248/419 Primary Examiner-W11liam H. Schultz Attorney, Agent, or Firm-Berman, Bishoff & Platt 57 ABSTRACT Mechanism operable to adjust the height of the seat in relation to the vehicle floor. The mechanism includes crossed levers arranged in pairs with the inner levers of the two pairs connected to one another by a torsion rod. The two pairs of levers are connected to one another by a transverse pivot shaft and corresponding ends of the outer levers of the pairs are connected to sliding pivot blocks. Wedge-shaped or cam-action plates arranged inwardly of the lever pairs are slidably connected to said shaft and also to a crossbrace assembly which is slidably forwardly and rearwardly of the seat relative to said pairs of crossed levers by means of a screw and nut mechanism.

3 Claims, 5 Drawing Figures PAIENIEM lsmlaaa SHEEI 20F 4 PATENTEDHM 12 1914 SHEET 3 OF 4 nNN un lfl- 4 .Ulllllrl ll lllllll llll II 3 km mi E v 4 QN v PATENTEUHHV 12 M 3.847338 snzsmnra E /49 m /////A ADJUSTABLE HEIGHT SEAT This invention relates to motor vehicle seats having meansoperable to adjust the height thereof.

It is the principal object of the present invention to provide an adjustable height seat whose overall weight is reduced compared with that of conventional adjustable height seats whose manufacturing cost is lower than that of a conventional seat and which will not give rise to an objectionable degree of scuffing.

Accordingly, the present invention consists in an adjustable height seat which includes a sea frame having spaced side members and spaced front and rear members all of which are rigidly connected to one another; two spaced lever pairs disposed parallel to one another in substantially vertical planes, the inner lever of one lever pair being connected to the inner lever of the pair by a torsion rod whose non-circular-section ends extend through complementary holes in said inner levers and are rivetted thereto; the levers in each lever pair being pivotally connected to one another in X configuration by a shaft extending through the two spaced lever pairs; corresponding one ends of corresponding one levers of each lever pair being rivetted to corresponding ones of said seat frame members; corresponding one ends of the corresponding other levers of each lever pair being connected by pin-and-slot connections tosaid corresponding ones of said seat frame members at locations spaced from the rivetting of the ends of said corresponding one levers thereto, the pin being carried by the lever and the closed slot being formed in the seat frame member; the corresponding other ends of said corresponding one levers of each lever pair having a pinand-slot connection with bracket members, the pin being carried by the lever and the closed slot being formed in the bracket member; the corresponding other ends of said corresponding other levers of each lever pair being rivetted to other bracket members which are spaced from the first-mentioned bracket members; two wedge-shaped plates generally vertically disposed and located in the vicinities of each lever pair and located inwardly of the lever pairs, each wedgeshaped plate having freedom for sliding movements relative both to said shaft and to said seat frame members and being so slidably mounted with the interpostion of elements of synthetic resin material having a low coefficient of friction between metal parts; said wedgeshaped plates being interconnected by a connecting piece which carries a nut of a screw and nut mechanism; whereby rotation of the screw in the nut will cause displacement of said wedge-shaped plates relative to said shaft and said seat frame members to alter the angular relationships between the lever of each lever pair as permitted by said pin-and-slot connections, with resultant adjustment of the spacing between the said bracket members on the one hand and the seat frame members on the other hand.

In a preferred embodiment of said adjustable height seat, each of said wedge-shaped plates has at its vertically separated non-parallel edges flanges which are substantially normal to the general plane of the plate, the flange or flanges at one of said edges engaging a guide secured to the respective seat frame member and the flange or flanges at the other of said edges engaging a shaped wedge block, which is supported by said shaft. Preferably, each of said wedge blocks is made of DEL- RIN (Registered Trade Mark) whereas one or more elements of DELRIN are interposed between said guide and the flange or flanges which are at said one edges of the wedge-shaped plates.

Again, preferably, the pin-and-slot connections between said lever ends and the seat frame members and the bracket members are by way of a sliding pivot blocks connected to the lever ends and slidable along said closed slots.

Said bracket members are securable in any desired manner to the slides of slide and guide assemblies of which the guides are securable to the vehicle floor to permit fore and aft movements of the whole seat. The seat may also be provided with releasable stop means operable to secure the whole seat in any position (fore and aft of the vehicle) to which said seat has been moved.

The present invention will now be more particularly described with reference to the accompanying drawings in which:

FIG. 1 illustrated in front elevation an adjustable height seat mounted upon a seat slide mechanism which permits fore and aft movement of the entire seat;

FIG. 2 illustrates a top plan view of the assembly illustrated in FIG. I;

FIG. 3 illustrates a side elevation of the assembly illustrated in FIG. 1;

FIG. 4 illustrates a section on a medial plane through a wedge retaining block; and

. FIG. 5 is a half section on the line V-V in FIG. 4, showing clearly the cross-sectional shape of the slot with which said block is formed.

Referring to the drawings, there is illustrated a seat frame which consists of interconnected side members ll, 12 and front and rear members l3, 14. All of said members, 11,12,13, are of angle section. Secured to the underside of the side members l1, 12 in transversely aligned positions are two parallel slides, 15, 16, said slides being so secured as by the rivets 17 illustrated. Two wedge-shaped plates 18, 19 have outwardly turned flanges at their opposed non-parellel edges, the flanges indicated by the reference numeral 20 having slide pads 21 made of DELRIN fitted thereto and said pads being arranged in the relevant one of the slides 15, 16. The flanges indicated by the reference numeral 22 are engaged by and are arranged for movement in a wedge retaining block 23 in a manner and for a purpose which will be hereinafter described.

The wedge-shaped plates 18, 19 are connected to one another by a crossbrace 24 both of whose ends are formed to provide two tongues 25 which extend through complementary holes in said plates and are then peened over upon assembly, said tonuges only being illustrated at one end of the crossbrace 24 in FIG. 2. The plates l8, 19 must be set parallel to one another and the crossbrace 24 must be at right angles to each of said plates. The crossbrace carries a nut 26 whose internal thread engages the external thread of a screw 27. A nut and washer 28 is screwed on to one end of the screw 27 and said screw extends through a thrust bearing 29 which is supported in a part of the front member 13. The portion of the bearing 29 which extends into said part of the front member 13 is of noncircular section (e.g., square with the comers of the square chamfered off) as also is the hole in which it is accommodated so that said bearing is prevented from rotating when the screw 27 is rotated. An E-clip 30 maintains the relative positions of the screw 27, the bearing 29 and the relevant part of the front member 13.

The front end of the screw 27 is provided'with a crank handle 31 and it will be seen that rotation of said handle 31 will cause displacement of the plates 18, 19 and the pads 21 along the slides 15, 16.

Two spaced lever pairs are provided, outwardly of the plates 18, 19 which are disposed parallel to one another in substantially vertical planes and one of said lever pairs is visible in FIG. 3. Each lever pair consists of a so-called inner lever 32 and a so-called outer lever 33 which are connected to one another in X configuration by a shaft 34 which extends tranversely right across the seat frame.

The rear end of the lever 33 is pivotally connected at 35 to the vertically disposed web of the relevant side member 11 or 12. By contrast, the front end of the lever 32 is pivotally connected to a sliding block 36 of which a part extends through an elongated slot 37 formed in said vertically disposed web.

In a similar manner, the rear end of the lever 32 is pivotally connected at 38 to the relevant one of two vertically arranged lugs 39 of a bracket 40 which are secured to two slides 41 as by nuts 42 which are screwed on to bolts 43 which could be integral with said slides. Another crossbrace 44 is secured to said slides 41 in a manner similar to that just described and said crossbrace 44 has vertically arranged lugs 45 having elongated slots 46 formed therein. The front end of the lever 33 is pivotally connected to a sliding block 47 of which a part extends through said elongated slot 46.

v 32 and the shaft 48 into a unitary structure.

The shaft 34 carries the two wedge retaining blocks 23 which were referred to above and which are to be seen in FIGS. 1, 3, 4 and 5. It will be seen from FIG. 4 that each block 23 is formed to provide a sleeve portion havinga bore 49 therethrough, through which the shaft 34 is intended to extend, and a slot 50 which extends in a direction at right angles to the longitudinal axis of said bore 49. The slot 50 is intended to accommodate the opposed flanges 22 of the relevant wedgeshaped plate 18 or 19 as can clearly be seen in FIG. 1. The blocks 23 are made of a material having a low coefficient of friction (for example, DELRIN) and said blocks are maintained in their correct positions on the shaft 34 by circlips 51.

Rotation of the handle 31 in the appropriate direction will cause the screw 27 to rotate in the nut 26 which is fixed to the crossbrace 24 and this will result in the plates 18, 19 being drawn towards the front of the seat frame. The pads 21 on the flanges 20 of said plates will slide along and within the slides 15, 16 and the flanges 22 of said plates will slide along and within the slots 50 in the blocks 23. As will be evident from FIG. 3, any sliding movement of the plates 18, 19 relative to the blocks 23 must result in vertical displacement of the seat frame towards or away from the slides 41 and, in the particular case being considered, said seat frame 10 will be moved away from said slides 41, thereby raising the seat frame. The resultant vertical movement of the shaft 34 accommodated or permitted by movement of the several sliding blocks 36, 47 along the associated slots 37, 46.

The mechanism permitting fore and aft movements of the entire seat has not been described except for the slide 41 because such arrangements are well-known and do not form part of the present invention. Similarly, it is not thought to be necessary to describe the manner in which the guide rail parts of such mechanism are secured to the vehicle floor, nor the manner in which the seat pan itself is secured to the members 14, 52.

What I claim as my invention and desire to secure by Letters Patent of the United States is:

1. An adjustable height seat which includes a seat frame having spaced side members and spaced front and rear members all of which are rigidly connected to one another; two spaced lever pairs disposed parallel to one another in substantially vertical planes, the inner lever of one lever pair being connected to the inner lever of the other lever pair by a torsion rod having non-circular-section ends extending through complementary holes in said inner levers and being rivetted thereto; the levers in each lever pair being pivotally connected to one another in X-configuration by a shaft extending through the two spaced lever pairs, said shaft being spaced from and non-coaxial with said torsion rod; corresponding one ends of corresponding one levers of each lever pair being pivotally rivetted directly to corresponding ones of said seat frame members; corresponding one ends of the corresponding other levers of each lever pair being connected by pin-and-slot connections directly to said corresponding ones of said seat frame members at locations spaced from the rivetting of the ends of said corresponding one levers thereto, the pin being carried by the lever and the slot being formed in the seat frame member; the corresponding other ends of said corresponding one levers of each lever pair having a pin-and-slot connection with bracket members, the pin being carried by the lever and the slot being formed in the bracket member; the corresponding other ends of said corresponding other levers of each lever pair being rivetted to other bracket members which are spaced from the first-mentioned bracket members; two wedge-shaped plates generally vertically disposed in the vicinities of each lever pair and located inwardly of the lever pairs, each of said wedge-shaped plates having vertically separated nonparallel edges with flanges thereon which are substantially normal to the general plane of the plate, the flanges at one of said edges engaging a slide secured to the respective seat frame member and the flanges at the other of said edges engaging a wedge retaining block formed solely of a synthetic resin material having a low coefficient of friction which is supported by said shaft, each of said wedge retaining blocks being formed with a bore for the accommodation of part of said shaft and with a slot at right angle to and spaced above said bore for the guided sliding of ssid flanges at said other edges, each wedge-shaped plate having freedom for sliding movements relative both to said shaft and to said seat frame and being so slidably mounted with the interposition of additional elements of synthetic resin material having a low coefficient of friction between metal parts, said wedge-shaped plates being interconnected centrally by a connecting piece which carries a nut of a screw and nut mechanism, whereby rotation of the screw in the nut will cause displacement of said wedgeshaped plates relative to said shaft and said seat frame to alter the angular relationships between the levers of each lever pair as permitted by said pin-and-slot connections, with resultant adjustment of the spacing between the said bracket members and the seat frame.

2. An adjustable height seat as claimed in claim 1, wherein said additional elements of synthetic resin main a direction transverse to said bore. 

1. An adjustable height seat which includes a seat frame having spaced side members and spaced front and rear members all of which are rigidly connected to one another; two spaced lever pairs disposed parallel to one another in substantially vertical planes, the inner lever of one lever pair being connected to the inner lever of the other lever pair by a torsion rod having noncircular-section ends extending through complementary holes in said inner levers and being rivetted thereto; the levers in each lever pair being pivotally connected to one another in Xconfiguration by a shaft extending through the two spaced lever pairs, said shaft being spaced from and non-coaxial with said torsion rod; corresponding one ends of corresponding one levers of each lever pair being pivotally rivetted directly to corresponding ones of said seat frame members; corresponding one ends of the corresponding other levers of each lever pair being connected by pin-and-slot connections directly to said corresponding ones of said seat frame members at locations spaced from the rivetting of the ends of said corresponding one levers thereto, the pin being carried by the lever and the slot being formed in the seat frame member; the corresponding other ends of said corresponding one levers of each lever pair having a pinand-slot connection with bracket members, the pin being carried by the lever and the slot being formed in the bracket member; the corresponding other ends of said corresponding other levers of each lever pair being rivetted to other bracket members which are spaced from the first-mentioned bracket members; two wedge-shaped plates generally vertically disposed in the vicinities of each lever pair and located inwardly of the lever pairs, each of said wedge-shaped plates having vertically separated non-parallel edges with flanges thereon which are substantially normal to the general plane of the plate, the flanges at one of said edges engaging a slide secured to the respective seat frame member and the flanges at the other of said edges engaging a wedge retaining block formed solely of a synthetic resin material having a low coefficient of friction which is supported by said shaft, each of said wedge retaining blocks being formed with a bore for the accommodation of part of said shaft and with a slot at right angle to and spaced above said bore for the guided sliding of ssid flanges at said other edges, each wedge-shaped plate having freedom for sliding movements relative both to said shaft and to said seat frame and being so slidably mounted with the interposition of additional elements of synthetic resin material having a low coefficient of friction between metal parts, said wedge-shaped plates being interconnected centrally by a connecting piece which carries a nut of a screw and nut mechanism, whereby rotation of the screw in the nut will cause displacement of said wedge-shaped plates relative to said shaft and said seat frame to alter the angular relationships between the levers of each lever pair as permitted by said pin-and-slot connections, with resultant adjustment of the spacing between the said bracket members and the seat frame.
 2. An adjustable height seat as claimed in claim 1, wherein said additional elements of synthetic resin material having a low coefficient of friction include elements which are interposed between the flanges at said one of said edges and the slides with which said flanges coact.
 3. An adjustable height seat as claimed in claim 1, wherein each of said wedge retaining blocks comprises a body having a rectangular base as its upper surface, and a depending portion of triangular cross-section said bore passing throuGh said body from end to end, and said slot being formed in said upper surface and lying in a direction transverse to said bore. 